[Feature]: Support color_temp_kelvin for light temperature control

[niquitoooo]

Requirements

• I have updated Mushroom to the latest available version
• I did a search to see if there is a similar issue or if a pull request is open.

Is your feature request related to a problem?

Currently, Mushroom Light Card uses color_temp (mireds) when controlling color temperature.

However, many modern Home Assistant integrations now use color_temp_kelvin instead, and may reject color_temp, causing errors like:

"extra keys not allowed @ data['color_temp']"

Thanks for your awesome work on Mushroom! 🙌

Describe the solution you'd like

Expected behavior

• Automatically detect if the light supports color_temp_kelvin
• Use color_temp_kelvin instead of color_temp when available

Why this matters

This would improve compatibility with newer integrations and avoid errors when using the color temperature slider.

Describe alternatives you've considered

No response

Additional context

No response

[DUXANATOR]

+1
too many object uses color_temp_kelvin now.
Add support please

[nilskliesing]

I would appreciate this change very much.
After upgrading Home Assistant to 2026.03 the Light Card Temperature setting is no longer working with my ZigBee lights.

Thank you for your great work!